In fields such as drug screening and biotechnology, biochemical reactions of substances and the like are tested. In the testing, a microplate is used as a container for containing drug solution and test substances with which cultivation and biochemical reactions are performed. The testing, usually performed systematically targeted for a large number of samples, processes a plurality of microplates in one testing for dispensing operation, componential analysis, and others.
Under the circumstances, as disclosed in Japanese Patent Unexamined Publication No. H11-223636, such a structure is known that is equipped with a feeding device for stocking a plurality of microplates; and a plate conveying mechanism for conveying microplates extracted from the feeding device, as a dedicated processing apparatus for performing the above-mentioned processes automatically. In this conventional example, microplates are individually contained in a storage rack provided with a plurality of plate placing positions; when feeding, microplates are extracted one by one by means of a plate conveying mechanism of the ceiling-travel robot type, and are transferred to the dispensing stage; and microplates having undergone the dispensing operation are returned into the storage rack.
A well for containing liquid, provided in a microplate, is open at its top surface. Therefore, when storing a microplate with liquid injected into its well, having undergone the dispensing operation, a lidded microplate may be used for isolating the injected liquid from the outside atmosphere, depending on a purpose of testing. In such a case, the lid needs to be attached and detached when performing processes such as a dispensing operation for the microplate, and thus the microplate processing apparatus requires a function for attaching and detaching a microplate lid.
In the above-mentioned conventional example, for instance, the apparatus is equipped with a lid removing unit therein, and microplates individually move to the lid removing unit by the plate conveying mechanism every time before and after a dispensing operation is performed.
However, in the above-mentioned conventional example, only one set of lid removing unit is arranged at a fixed position. Consequently, a large number of microplates requiring being processed continuously make it difficult to attach and detach lids efficiently, which causes the entire processing to be inefficient.